Silencing of Lysyl Oxidase RNA Interference Suppresses Breast Cancer Metastasis

Breast cancer is one of the malignant tumors that occur most commonly in women. The incidence shows an increasing tendency every year that maybe associates with some wrong modern lifestyle (Loh et al., 2011; Sulaiman et al., 2011). The main reason for the treatment failure is the metastasis and invasiveness of the cancer. Therefore, it is very important to find the possible mechanism of the recurrence and the metastasis of breast cancer. Lysyl oxidase (LOX) is an amine oxidase that crosslinks collagens and elastins in the extracellular matrix. LOX controls both the structure and the tensile strength of ECM, and thus acts to preserve tissue integrity. Recent studies indicated that LOX promotes malignant progression in cancer (Peyrol et al., 1997; Woznick et al., 2005; Fong et al., 2007). However, the specific mechanism of LOX-mediated promotion of breast cancer metastasis is unclear. In our research, we investigated the possible mechanism of LOX gene affecting on the invasion and metastasis of breast cancer cells by RNA interference (RNAi). LOX-RNAi-LV was constructed to lower the LOX gene expression level in the MDA-MB-231 breast cancer cells, so that we could observe how LOX gene regulates metastatic colonization and growth of breast